Compressed gas supply system

ABSTRACT

In a compressed gas supply system, particularly for supplying helium under pressure to inflate balloons, as in balloon vending machines, two tanks containing gas under pressure are connected to a supply line through respective pressure regulating valves set to feed gas under relatively low pressures from the respective tanks to the supply line, and the regulating valve associated with one of the tanks is set to feed at a pressure slightly higher than that at which the other regulating valve is set to feed so that gas is initially supplied from the tank whose regulating valve is set at the slightly higher pressure and feeding of gas from the other tank commences automatically only when the pressure of gas in the first tank has been reduced substantially to the pressure setting of the regulating valve for that other tank.

United States Patent Begleiter Feb. 22, 1972 [54] COMPRESSED GAS SUPPLY SYSTEM Primary Examiner-Samuel B. Rothberg [72] Inventor Manny Begaener Bronx Assistant ExaminerWilliam H. Wright [73] Assignee: Miner Indu trie In N w Y k, NY, AttorneyLewis 1-1. Eslinger, Alvin Sinderbrand and Curtis,

M & Saff d 221 Filed: Apr. 29, 1970 or 211 Appl. No.: 32,786 1 1 ABSTRACT In a compressed gas supply system, particularly for supplying [52] us. (:1 ..137/113, 137/114, 141/167 helium under P inflate balloons, as in balloon vend- [51] 1nt.C1. ..G05d 16/06 ing machines two tanks containing gas under Pressure are [58] Field of Search ..137/111 113 112 114- connected to a pp y line hrough respective pressure regui lating valves set to feed gas under relatively low pressures from the respective tanks to the supply line, and the regulating 56 R f m d valve associated with one of the tanks is set to feed at a pres- 1 e e sure slightly higher than that at which the other regulating UNITED STATES PATENTS valve is set to feed so that gas is initially supplied from the tank whose regulating valve is set at the slightly higher pressure and 2,389,667 11/1945 Hudson 137/1 13 feeding of gas from the other tank commences automatically 310011541 9/1961 13 only when the pressure of gas in the first tank has been 3,536,110 10/ 1970 141/ 16 reduced substantially to the pressure setting of the regulating 2,168,701 8/1939 1 37/1 13 valve for that other tank 2,380,956 8/1945 .....137/113 2,775,980 1/1957 Renaudie 137/1 13 5 Claims, 2 Drawing Figures 3s v 33 I 37 25 I 5'5 52 34 36 25 W} T m FIG. 2.

INVENTOR.

MANNY BEGLEITER BY ATTORNEY COMPRESSED GAS SUPPLY SYSTEM This invention relates generally to compressed gas supply systems, and more particularly is directed to gas supply systems of the type in which the compressed gas is stored in a plurality'of tanks or bottles and is intended to be discharged therefrom in sequence.

In compressed gas supply systems which store the gas under pressure in tanks or bottles, it has become standard to employ two or more tanks from which the gas is discharged in sequence so that when the gas supply in one tank is exhausted, feeding can continue from another tank and the exhausted tank can be replaced by a filled tank without interrupting the gas supply. The foregoing arrangement is particularly advantageous when the site of the compressed gas supply system is remote from the storage depot for the compressed gas tanks so that only periodic service calls are feasible to determine the extent of the compressed gas supply that remains at the remote site. If a single tank is employed, the supply of compressed gas therein may not be fully exhausted at the time of a service call, in which case the existing options require either replacing the partly filled tank or running the risk that the supply of compressed gas will run out before the next service call. However, if two or more tanks discharging in sequence are provided, a tank has to be replaced at each regularly scheduled service call only if that tank is substantially empty, and assurance is thereby provided that at least one full tank is available after each service call to ensure an uninterrupted supply of the compressed gas until the next service call.

Although the above advantages of compressed gas supply systems having a plurality of tanks from which the gas is discharged in sequence have been long recognized, the existing systems of that type have used relatively complex and costly special crossover valves to achieve the discharge from the tanks in sequence.

Accordingly, it is an object of this invention to provide a compressed gas supply system in which the gas is stored in a plurality of tanks and the discharging of the gas from the tanks in sequence is achieved by an arrangement of readily available and relatively inexpensive pressure regulating valves.

Another object is to provide a helium supply system having a plurality of tanks containing helium under pressure and from which the helium is discharged in sequence, that is, from one tank until the supply of helium therein is substantially exhausted and then from another tank.

7 Still another object is to provide a helium supply system, as aforesaid, which is particularly suited for inflating balloons, as in a balloon vending machine.

ln accordance with an aspect of this invention, a compressed gas supply system particularly for supplying helium under pressure to inflate balloons, as in a balloon vending machine, comprises first and second tanks containing gas under high pressure and being connected to a supply line through respective first and second pressure regulating valves set to feed the gas under relatively low pressures from the respective tanks to'the supply line, and the first pressure regulating valve is set to feed at a pressure slightly higher than that at which the second pressure regulating valve is set to feed, so that gas will be initially supplied, on demand, from the first tank whose regulating valve is set at the slightly higher pressure and feeding of gas from the second tank will commence automatically only when the pressure of gas in the first tank has been reduced substantially to the pressure at which the second pressure regulating valve is set to feed.

In a preferred embodiment of the invention, a compressed gas supply system, as described above, is further provided with an additional pressure regulating valve interposed in the supply line downstream from the first and second pressure regulating valves and set to feed gas at a pressure below that at which either of the first and second regulating valves is set so that the pressure of the gas discharged from the supply line will be uniformly at the pressure setting of such additional regulating valve whether such gas originates in the first or the second tank.

The above, and other objects, features and advantages of this invention, will be apparent in the following detailed description of an illustrative embodiment-which is to be read in connection with the accompanying drawing, in which:

FIG. 1 is a diagrammatic view showing a compressed gas supply system according to this invention; and

FIG. 2 is a schematic sectional view of one of the pressure regulating valves included in the system of FIG. 1.

Referring to the drawing in detail, and initially to FIG. 1 thereof, it will be seen that a compressed gas supply system 10 according to this invention, as there shown, comprises first and second containers 11 and 12, for example, in the form of metal tanks or bottles, containing a gas such as helium which is initially under a relatively high pressure, for example, a pressure of 2,200 psi. The tanks or bottles 11 and 12 have the usual outlet assemblies which include shutoff valves 13 and 14 and are separably connected to branch conduits 15 and 16, respectively, extending to a supply conduit 17. The supply conduit 17 may be connected, for example, through a flexible hose extensions 17a, to a device for utilizing the gas under pressure to be supplied thereto through conduit 17. Such device, as shown, may be in the form of a nozzle 18 through which balloons may be inflated with the gas fed thereto, for example, as in balloon vending machines disclosed in either of US. Pat. No. 3,191,801, and No. 3,380,490, or in the copending application for a US. Pat. identified as Ser. No. 746,168, filed July 19, 1968, now US. Pat. No. 3,535,927, and all having a common assignee herewith.

In such balloon vending machine, successive balloons are inflated with a mixture of helium under pressure and compressed air. Thus, when the compressed gas supply system according to this invention is to form part of a balloon vending machine of the described type, the supply of helium for inflating the balloons'is contained in tanks or bottles 1 1 and 12, and the system further comprises a source of compressed air which may be constituted by an electric motor-driven air compressor 19 having its outlet connected to a compressed air tank or air pressure accumulator 20 from which there extends a com pressed air supply line or conduit 21 connected, as by a Tee 22 with the supply conduit 17. The supplying of helium under pressure and compressed air to nozzle 18 may be selectively controlled, as by solenoid valves SV and SV respectively interposed in conduits 17 and 21 and being normally closed to block the passage of helium and compressed air through the respective conduits. The solenoid valves SV and SV may be selectively energized through suitable electric circuits (not shown) which form no part of the present invention. When energized, valves SV and 8V open to permit the passage of helium under pressure and compressed air, respectively, through the associated conduits 17 and 21 to the nozzle 18 for inflating a balloon engaged with the latter. Thus, by controlling the periods of energization of valves SV and 8V one can select the proportions of helium and compressed air in the mixture thereof to be employed for inflating each balloon. Where the system is intended to supply compressed air as well as helium under pressure, as shown check valves 23 and 24 may be interposed in conduit 17 between valve SV and Tee 22, and in conduit 21 between valve SV and Tee 22, respectively.

As previously mentioned, it is a principal object of this invention to ensure that, in the compressed gas supply system 10, the helium or other gas under pressure contained in the tanks or bottles 11 and 12 will be initially supplied from only one of the tanks, for example, from the tank 11, and that gas will be supplied from the other tank 12 only when the supply of gas in the first tank 11 has been substantially exhausted. In accordance with the present invention, the foregoing objective, that is, the supplying of the gas under pressure from the tanks 11 and 1 2 in sequence, is achieved simply by providing pressure regulating valves 23 and 24 respectively interposed in the branch conduit 17. Each of pressure regulating valves 23 and 24 may be of a commercially available type, for example, as is obtainable from Air Products and Chemical, lnc., Allentown, Pennsylvania, under the designation Style 2200, Comm. No.23l6222035, and is operative to maintain a preselected relatively low pressure in the respective conduit 15 or 16 at the downstream side of the pressure regulating valve and to open for feeding of gas from the respective tank 1 1 or 12 only when a demand for such gas causes the pressure at the downstream side of the valve 23 or 24 to fall below its preselected pressure.

For example, as shown on FIG. 2 which schematically represents pressure regulating valve 23, each of pressure regulating valves 23 and 24 may comprise a housing 25 having a partition 26 extending thereacross to divide the interior of housing 25 into compartments 27 and 28 which are respectively connected with the upstream and downstream sections of the respective conduit, for example, the sections 15a and 15b of conduit 15. An opening 29 is provided in partition 26 to afford communication between compartments 27 and 28 and the periphery or edge of opening 29 defines a seat for a valve member 30. A valve stem 31 extends from valvemember 30 and is connected to a flexible diaphragm 32 which extends across an extension 33 of housing 25 so as to divide the interior of housing extension 33 into chambers 34 and 35 which are isolated from each other. Chamber 34 is vented to compartment 28,as by the vent opening 36, so that the pressure in the downstream conduit section 15b acts in chamber 34. The other chamber 35 is vented to the atmosphere, as by the vent opening 37. It will be apparent that the pressure differential between the gas pressure in downstream conduit section 15b, which acts in chamber 34, and the atmospheric pressure acting in chamber 35 will act on diaphragm 32 so as to urge valve member 30 against its seat in opening 29. On the other hand, a compression spring 38 adjustably loaded by a screw 39 acts against diaphragm 32, and hence against stem 31 of valve member 30, to urge the latter away from its seat defined by the edge of opening 29. Thus, by adjusting screw 39, one can preselect the relatively low pressure at which gas will be fed from the respective tank 11 or 12 through the pressure regulating valve 23 or 24 to the downstream section of the respective conduit 15 or 16 and then to the supply conduit 17.

If the gas pressure in downstream conduit section 15b is equal to or greater than the preselected pressure established by adjustment of screw 39, such downstream pressure acting in chamber 34 will be sufficient to overcome the force of spring 38 and thereby maintain valve member 30 in its closed or seated position.v However, if the downstream pressure falls below the preselected value, for example, when solenoid valve SV is opened to feed helium under pressure to nozzle 18, then the force of spring 38 is dominant with respect to the pressure in chamber 34 acting on diaphragm 32 and valve member 30 is opened or unseated sufficiently to return the downstream pressure to the preselected value by the feeding of gas under pressure from the respective tank.

In accordance with the present invention, the pressure at which one of the pressure regulating valves, for example, the valve 23, is operative to feed gas from the respective tank 11 to supply conduit 17 is made slightly greater, for example, p.s.i. greater, than the pressure at which the other pressure regulating valve 24 is operative to feed gas from its tank 12 to supply conduit 17. For example, when the tanks 1 l and 12 initially contain helium under a pressure of 2,200 p.s.i., as previously mentioned, pressure regulating valves 23 and 24 may be desirably set or arranged to feed gas from their respective tanks 11 and 12 only when the pressures in the downstream sections b and 16b of conduits 15 and 16 decline below pressures of 40 and 35 p.s.i., respectively.

In the example given above, and assuming that tanks 11 and 12 are both full, that is, contain helium under a pressure of approximately 2,200 p.s.i., pressure regulating valve 23 will establish a pressure of 40 p.s.i. in downstream section 15b of branch conduit 15 and also in downstream section 16b of branch conduit 16 by reason of the mutual connection of conduits l5 and 16 to supply conduit 17. When solenoid valve SV is opened to create a demand for helium under pressure,

the pressure in conduit section 15b will decline and, in response to such pressure drop, pressure regulating valve 23 will open in order to maintain the pressure of 40 p.s.i. in conduit section 15b and also in conduit section 16b. Since the pressure of 40 p.s.i. in conduit section 16b at the downstream sideof pressure regulating valve 24 is greater than the preselected pressure of 35 p.s.i. at which valve 24 is operative to feed gas from its associated tank 12, pressure regulating valve 24 will remain closed, and thus the demand for helium under pressure will be satisfied by the feeding of gas from tank 1 1 alone.

However, when the supply of helium in tank 11 is almost exhausted, that is, when the pressure of helium in tank 11 has been reduced to the pressure at which the pressure regulating valve 24 associated with tank 12 is operative to feed gas from the latter, then pressure regulating valve 23 can no longer maintain a pressure in conduit sections 15b and 16b which is in excess of the pressure at which valve 24 opens. Thus, in the example mentioned above, when the pressure in tank 11 has been reduced to 35 p.s.i., the further opening of solenoid valve SV to create a demand for helium drops the pressure in con-v duit section 16b below 35 p.s.i. and, in response to such pressure drop, pressure regulating valve 24 opens sufficiently to supply the demanded helium from tank 12 at the preselected pressure of 35 p.s.i. Thereafter, any further demand for helium under pressure is satisfied by the feeding of such gas from tank 12 and, although pressure regulating valve 23 remains open, a pressure of approximately 35 p.s.i. is maintained in tank 11, that is, a relatively small quantity of helium remains in tank 11.

If desired, a pressure gauge 40 may be connected with one, or each of conduit sections 15b and 16b to indicate the pressure existing therein. It will be apparent that, when gauge 40 indicates the pressure for which valve 23 has been set, such indication establishes that feeding of helium is still taking place from the supply in tank 11 and, therefore, that tank 12 still contains a supply of helium. On the other hand, if gauge 40 indicates the pressure for which valve 24 has been set, then such indication establishes-that tank 11 has been substantially exhausted and that feeding of helium is then occurring from the second tank 12. In the latter case, tank ll may be replaced with a filled tank in order to ensure that there will remain an adequate supply of helium until the next inspection of the balloon vending machine or other device with which the compressed gas supply system is associated. The fact that a minimum pressure of helium is maintained in tank 11 when feeding of helium from tank 12 commences is desirable in that the small amount of helium that thus remains in tank 11 avoids the necessity of cleaning or purging of the tank before its refilling.

With the system 10 to the extent described above, the pressure of helium supplied to nozzle 18 would be greater, for example, by 5 p.s.i., when such helium is being supplied from the tank ll than when the helium supply is coming from tank 12. When the compressed gas supply system 10 is provided in a balloon vending machine, as mentioned above, such differential pressure in the supply of helium to nozzle 18 would be undesirable in that it would alter the pressures with which the balloons are inflated and thereby vary the sizes of the inflated balloons. Therefore, in the system 10 intended for use in balloon vending machines, a third pressure regulating valve 41, which may be similar to the valves 23 and 24, is interposed in supply conduit 17 between solenoid valve SV, and the end of conduit 17 to which branch conduits 15 and 16 are joined. The third or additional pressure regulating valve 41 is adjusted or otherwise made operative to feed helium to conduit 17, at the downstream side of valve 41, at a pressure that is less than the lowest of the pressures at which the valves 23 and 24 are operative to feed. For example, when valves 23 and 24 are respectively operative to feed at pressures of 40 and 35 p.s.i., pressure regulating valve 41 may be made operative to feed so as to maintain a pressure of 7 psi. at the downstream side thereof. With the foregoing arrangement, it will be apparent that the pressure of helium reaching nozzle 18 for inflating balloons is always at a pressure of 7 p.s.i. whether such gas is being fed from tank 11 or from tank 12. A further advantage of providing the additional pressure regulating valve 41, as shown on FIG. 1, resides in the fact that a two-stage reduction of the pressure is thereby obtained, that is, a first reduction of pressure by the valve 23 or the valve 24 from the high pressure in tank 11 or 12, and a final reduction of pressure by the valve 41 to the relatively low pressure required for balloon inflation. lt has been found that such two-stage reduction of pressure is desirable in that, in the absence of the second pressure reduction by valve 41, it is difficuit to accurately obtain the necessa ry pressure reduction from the high pressure in tank 11 or 12 to the low pressure required for inflating balloons.

It will be apparent that, in the system embodying this invention, the desired feeding of gas from tanks 1 l and 12, in sequence, is achieved through the use of conventional pressure regulating valves, and that the described system eliminates the necessity of specially designed, and hence costly crossover valves for achieving the sequential discharge of gas from the tanks.

The system 10 described above with reference to FIG. .1 cmploys two tanks 11 and 12 as the source of helium or other gas under high pressure. However, systems according to this invention may include three or more of such tanks connected throughrespective branch conduits to the supply conduit 17, and with pressure regulating valves, such as 23 and 24, being interposed in the respective branch conduits and being operative to feed gas at progressively different pressures.

Although an illustrative embodiment of the invention has been described in detail herein with reference to the drawing, it is to be understood that the invention is not limited to that precise embodiment, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope of spirit of the invention.

What is claimed is:

l. A compressed gas supply system comprising at least first and second containers of gas under relatively high pressure, supply conduit means, first and second branch conduit means extending from said first and second containers and opening at all times into said supply conduit means, first pressure regulating valve means interposed in said first branch conduit means and operative to open to feed gas from the first container to said supply conduit means at a first predetermined relatively low pressure only when the pressure in said first branch conduit means between said first pressure regulating valve means and said supply conduit means declines to the value of said first predetermined low pressure, and second pressure regulating valve means interposed in said second branch conduit means and operative to open to feed gas from said second container to said supply conduit means at a second predetermined relatively low pressure, which is slightly lower than said first predetermined low pressure, only when the pressure in said second branch conduit means between said second pressure regulating valve means and said supply conduit means declines to the value of said second predetermined low pressure, whereby gas is fed only from said first container until the pressure of gas therein is reduced to said second predetermined low pressure at which said second pressure regulating valve means is operative to feed and, thereafter, gas is automatically fed from said second container.

2. A compressed gas supply system according to claim 1, in which third pressure regulating valve means is interposed in said supply conduit means and is operative to feed gas therethrough at a pressure lower than either of said first and second low pressures at which said first and second pressure regulating valve means are operative to feed, whereby said supply conduit means delivers gas at said pressure at which said third pressure regulating valve means is operative to feed irrespective of the container from which the gas is being fed.

3. A compressed gas supply system according to claim 2, further comprising a nozzle to which said supply conduit means extends and through which balloons may be inflated with the gas fed thereto, and control valve means interposed in said supply conduit means to normally block the feeding of gas to said nozzle and being operable to permit the feeding of gas to said nozzle.

4. A compressed gas supply system according to claim 3, in which said gas under relatively high pressure in said containers is helium, and further comprising a source of compressed air and second supply conduit means extending from said source of compressed air to the first-mentioned supply conduit means at a location along the latter between said control valve means and said nozzle so that balloons may be inflated through said nozzle with a mixture of helium and air under pressure.

5. A compressed gas supply system according to claim 4, further comprising second control valve means interposed in said second supply conduit means to normally block the feeding of compressed air through said second conduit means to said nozzle and being operable to permit the feeding of compressed air, so that, by selective operation of the first mentioned control valve means and said second control valve means, the proportions of helium and compressed air in said mixture can be controlled. 

1. A compressed gas supply system comprising at least first and second containers of gas under relatively high pressure, supply conduit means, first and second branch conduit means extending from said first and second containers and opening at all times into said supply conduit means, first pressure regulating valve means interposed in said first branch conduit means and operative to open to feed gas from the first container to said supply conduit means at a first predetermined relatively low pressure only when the pressure in said first branch conduit means between said first pressure regulating valve means and said supply conduit means declines to the value of said first predetermined low pressure, and second pressure regulating valve means interposed in said second branch conduit means and operative to open to feed gas from said second container to said supply conduit means at a second predetermined relatively low pressure, which is slightly lower than said first predetermined low pressure, only when the pressure in said second branch conduit means between said second pressure regulating valve means and said supply conduit means declines to the value of said second predetermined low pressure, whereby gas is fed only from said first container until the pressure of gas therein is reduced to said second predetermined low pressure at which said second pressure regulating valve means is operative to feed and, thereafter, gas is automatically fed from said second container.
 2. A compressed gas supply system according to claim 1, in which third pressure regulating valve means is interposed in said supply conduit means and is operative to feed gas therethrough at a pressure lower than either of said first and second low pressures at which said first and second pressure regulating valve means are operative to feed, whereby said supply conduit means delivers gas at said pressure at which said third pressure regulating valve means is operative to feed irrespective of the container from which the gas is being fed.
 3. A compressed gas supply system according to claim 2, further comprising a nozzle to which said supply conduit means extends and through which balloons may be inflated with the gas fed thereto, and control valve means interposed in said supply conduit means to normally block the feeding of gas to said nozzle and being operable to permit the feeding of gas to said nozzle.
 4. A compressed gas supply system according to claim 3, in which said gas under relatively high pressure in said containers is helium, and further comprising a source of compressed air and second supply conduit means extending from said source of compressed air to the first-mentioned supply conduit means at a location along the latter between said control valve means and said nozzle so that balloons may be inflated through said nozzle with a mixture of helium aNd air under pressure.
 5. A compressed gas supply system according to claim 4, further comprising second control valve means interposed in said second supply conduit means to normally block the feeding of compressed air through said second conduit means to said nozzle and being operable to permit the feeding of compressed air, so that, by selective operation of the first mentioned control valve means and said second control valve means, the proportions of helium and compressed air in said mixture can be controlled. 